6561000 has 144 divisors (see below), whose sum is σ = 23027940. Its totient is φ = 1749600.

The previous prime is 6560999. The next prime is 6561001. The reversal of 6561000 is 1656.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

6561000 is a `hidden beast` number, since 656 + 10 + 0 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (6560999) and next prime (6561001).

It can be written as a sum of positive squares in 2 ways, for example, as 4435236 + 2125764 = 2106^2 + 1458^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (6561001) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1312198 + ... + 1312202.

Almost surely, 2^6561000 is an apocalyptic number.

6561000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6561000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11513970).

6561000 is an abundant number, since it is smaller than the sum of its proper divisors (16466940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6561000 is an frugal number, since it uses more digits than its factorization.

6561000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45 (or 10 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 6561000 is about 2561.4449047364. Note that the first 3 decimals coincide. The cubic root of 6561000 is about 187.2075440747.

Adding to 6561000 its reverse (1656), we get a palindrome (6562656).

The spelling of 6561000 in words is "six million, five hundred sixty-one thousand".